Office is available in several versions that are tailored to different computing environments and end-users. The desktop version is the most popular and widely used. It is available for computers running Windows or macOS operating systems. Microsoft also offers mobile apps for iOS and Android. Office on the Web is a version that runs in a web browser. Microsoft Office 365 has been promoted by Microsoft since 2013. It allows users to use the software and other services through a subscription model. Users receive feature updates for the life of the subscription, which includes new features and cloud computing integration, that are not available in the “on-premises” Office releases. Office 365 revenue surpassed traditional license sales in 2017. Microsoft also rebranded many of their standard Office 365 editions as Microsoft 365 to highlight their current inclusion of products, services, and software. Office 2019 is the current desktop version of Office. Office 2021 will be released on October 5, 2021.